This invention relates generally to electrical connectors and more specifically to electrical plug connectors that have an interface seal in the form of an elastomeric annulus.
U.S. Pat. No. 4,822,294 granted to Lisa J. McClearn Apr. 18, 1989 discloses a sealing grommet assembly for a wiring harness that includes mating electrical plug and socket connectors (22) and (24) having an interface seal of elastomeric material. The interface seal comprises an annular body that is mounted on the plug portion of the electrical plug connector (22) with its trailing axial end against a stop shoulder as best shown in FIG. 3 of the patent. This interface seal further comprises a plurality of flexible radial lips that extend radially outwardly of the annular body. The flexible radial lips are deflected into biased sealing engagement with an inner surface of a shroud of the mating electrical socket connector (24) when the electrical plug connector (22) is plugged in as shown in FIG. 4 of the patent.
See also U.S. Pat. No. 4,874,325 granted to Gregory L. Bensing, Joseph H. Gladd, and John A. Yurtin Oct. 17, 1989 for an electrical connector with an interface seal and U.S. Pat. No. 4,921,437 granted to Ralph M. Cooper, Dana Hollingsworth, John P. Kunkle and Donald G. Stillie May 1, 1990 for a sealed electrical connector assembly with a terminal retainer.
An ongoing problem with interface seal arrangements of the above noted type is seal bunching, especially when the elastomeric seal has a long span. Seal bunching occurs when the trailing axial end of the annular body rides up over the stop shoulder of the electrical plug connector body when it is plugged into the mating socket connector body. This allows the trailing axial end portion of the elastomeric seal to squirt out the open end of the shroud which results in a high engagement force requirement and a potential seal leakage problem.